Your annotation is good. 19. Rd3 Bxc3 20. Rxc3 leads to a pawn up rook ending in which black can probably hold a draw. 20. bxc3 is interesting to keep the initiative, but if black can get a rook to the c file he will win back a pawn.

23. Rd7 is either a blunder or a nice exchange sac, I'm not sure which

26. c4? doesn't seem that great, as the rook becomes tied to the pawn. In fact, black can win his pawn back with 26... e5. Better was 26. Nc3.

26... g5? Black fails to win a pawn or even set up some defensive resources, he is trying to win. e5 is obviously better, while h5 would have led to an easy draw. You can't blame him for trying to win when he's up an exchange though.